Whether it’s the possibility of a magnetic levitation train or the hyperloop idea proposed by Elon Musk, founder of PayPal, Tesla Motors and SpaceX, the route of potential alternative designs for California’s putative bullet train invariably follows Interstate 5 from just west of Bakersfield to the San Francisco Bay area.

That’s why the Thanksgiving week ruling by a Sacramento Superior Court judge forbidding the state’s High Speed Rail Authority from tapping billions of dollars in voter-approved state bonds for the project represents an opportunity and not a setback.

Yes, cries for a new popular vote on the bonds went up immediately after Judge Michael Kenny’s decision, but that’s unlikely anytime soon. So the best course now is to make this project sensible, and the way to do that is to look hard at its potential routes.

From the start, the route chosen by bullet train officials has made little sense. Yes, steep gradients on the north side of the Tehachapi mountains probably mean that, whatever its technology, the path will swing through the Antelope Valley cities of Palmdale and Lancaster, roughly tracking Highways 14 and 58 between Los Angeles and Bakersfield...